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. 2021 Feb;18(2):237-247.
doi: 10.1080/15476286.2020.1744320. Epub 2020 Apr 14.

LARP1 isoform expression in human cancer cell lines

Hagen Schwenzer  1 , Mai Abdel Mouti  1 , Pia Neubert  1 , Josephine Morris  1 , Joanne Stockton  2 , Sarah Bonham  3 , Martin Fellermeyer  1 , James Chettle  1 , Roman Fischer  3 , Andrew D Beggs  2 , Sarah P Blagden  1
Affiliations

LARP1 isoform expression in human cancer cell lines

Hagen Schwenzer et al. RNA Biol. 2021 Feb.

Abstract

LARP1 is an oncogenic RNA-binding protein required for ribosome biogenesis and cancer cell survival. From published in vitro studies, there is disparity over which of two different LARP1 protein isoforms (termed the long LI-LARP1 and short SI-LARP1) is the canonical. Here, after conducting a series of biochemical and cellular assays, we conclude that LI-LARP1 (NM_033551.3 > NP_056130.2) is the dominantly expressed form. We observe that SI-LARP1 (NM_015315.5> NP_056130.2) is epigenetically repressed and that this repression is evolutionarily conserved in all but a small subclade of mammalian species. As with other LARP family members, there are multiple potential LARP1 mRNA isoforms that appear to be censored within the nucleus. The capacity of the cell to modulate splicing and expression of these apparently 'redundant' mRNAs hints at contextually specific mechanisms of LARP1 expression.

Keywords: LARP1; RNA Binding Proteins; alternative protein isoforms; cancer.

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Conflict of interest statement

No potential conflict of interest was reported by the authors.

Figures

Figure 1.
Figure 1.
Isoforms of LARP1
Figure 2.
Figure 2.
Transcriptomic profile of LARP1 isoform expression
Figure 3.
Figure 3.
Analyzes of the mRNA expression of the short and long isoform in human cells
Figure 4.
Figure 4.
Identification of peptides specific for long isoform in four different human cell lines
Figure 5.
Figure 5.
Promoter of long isoform is demethylated and activated while promoter of short isoform is methylated and inactive
See this image and copyright information in PMC

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